The study aims to determine the digital literacy levels and opinions of classroom teachers who participated in eTwinning activities in Mersin province in the 2022-2023 academic year according to various variables. A mixed method was used in the study. The "Digital Literacy Scale" developed by Bayrakçı (2020) was used to collect quantitative data. The digital literacy scale consists of 6 sub-dimensions and 29 items: ethics and responsibility, general knowledge and functional skills, daily use, professional production, privacy and security, and social dimension. The research study group of the research consisted of 362 volunteer classroom teachers who participated in eTwinning activities working in Mersin province. The study’s qualitative data of the study were collected through semi-structured interviews with 7 classroom teachers using the interview form prepared by the researchers and the data were analyzed by content analysis. Within the scope of the research, the digital literacy levels of classroom teachers who participated in eTwinning activities were found to be high. In the interviews, the teachers stated that the eTwinning activity improved their digital literacy skills. As a result of the research, teachers who participated in professional development courses were found to have higher DLS scores than teachers who did not participate in professional development courses. It was concluded that the DLS scores increased as the duration of being a member of eTwinning and the duration of using technological devices increased. According to the findings of the qualitative analysis, teachers stated that eTwinning activities contributed to recognizing and using Web 2.0 tools, knowing e-safety rules, developing online communication skills and improving digital literacy skills.